Paint spraying apparatus



W. G. BLENMAN PAINT SPRAYING APPARATUS Nqv. 22, 1966 Filed July 22, 19635 Sheets-Sheet 1 I N VE NTOR. ZZfiZ/k'am G Elm/27017 f ATTORNEY Nov. 22,1966 G. BLENMAN 3,286,688

PAINT SPRAYING APPARATUS ATTORNEY 1965 w. G. BLENMAN 6,68

PAINT SPRAYING APPARATUS Filed July 22, 1953 5 Sheets-Sheet 5 IINVENTOR. Z fiZ/IIIM 6. 31617271021 ATTORNEY United States Patent3,286,688 PAINT SPRAYING APPARATUS William G. Blenman, Grosse Pointe,Mich, assignor to General Motors Corporation, Detroit, Mich, acorporation of Delaware Filed July 22, 1963, Ser. No. 296,572 6 Claims.((11. 118-323) The present invention relates to spraying apparatusparticulary adapted for painting automotive vehicle bodies and similarlarge-surface objects while passing through the spray booth of anassembly line.

The invention contemplates an improved paint spraying apparatus ormachine having an extensible spray-gunsu-pporting linkage of relativelyrigid compact inexpensive design, capable "of remote and conveyorsynchronized automatic control, and mountable in laterally spacedoverhead relation to a vehicle body conveyor line. In an illustrativeembodiment, a compound parallelogram linkage is pivotally mounted on anoverhead frame and is motor driven by suitable motion translating meansto provide constant-velocity straight-line reciprocating movement of aspray-gun-supporting boom or linkage, The spray gun or guns and theirsupporting linkage thus traverse the several offset surfaces of aconveyor transported vehicle body or similar workpiece between alaterally retracted position and an extreme extended position. A poweroperator associated with the gun supporting linkage is selectivelyenergizable to raise and lower the spray guns relative to the framesupported compound linkage and into proximate spraying relation normalto several offset vehicle body surfaces.

While the ilustrative embodiment of the invention is specificallydesigned for vehicle body painting, the invention may be adapted for usein painting relatively large surfaces on other objects and particularlywhile such objects are moving along an assembly line.

The foregoing and other objects, advantages and features of theinvention will be apparent from the following description of theillustrative embodiment, having reference to the accompanying drawings,in which:

FIGURE 1 is a side elevation-a l view illustrating the paint sprayapparatus of the invention in its intended operational environment andshows several extreme operational positions of the spray guns and theirsupporting linkages in full and phantom broken lines with reference toan overhead conveyor and a conveyor supported vehicle body which arealso shown in phantom broken lines;

FIGURE 2 is an elevational view taken substantially in the direction ofthe arrows indicated at 2-2 of FIG- URE 1;

FIGURE 3 is an enlarged perspective view of the spray apparatus ofFIGURES 1 and 2 with portions broken away to show certain structuraldetails.

Referring more particularly to the drawings, a paint spray apparatus ormachine illustrative of the invention is indicated generally by thereference numeral 10. This machine has an angled frame 11 of lightweighttruss construction and is suspended by resilient mounts 12 from overheadI-beams 13 in laterally spaced relation to an overhead conveyor. Forillustrative purposes, a conveyor transported vehicle body is shown inphantom broken lines at 14 in FIGURES 1 and 2. Each body is supported atopposite ends by a cradle-type hanger 15 suspended from a chain drivencarrier 16 which is roller mounted on an overhead I-beam rail 17extending longitudinally of the paint booth. A suitable pneumatic andelectrical control console 18 is secured to the vertical portion 19 ofthe frame 11. This console is operably connected to suitable manual andautomatic body style selecting controls 20 and 22 and adapted tosynchronize operation of Patented Nov. 22, 1966 the paint sprayingapparatus of the invention in accordance with vehicle (body movementrelative thereto.

In the illustrative embodiment, a laterally extending quadrilaterallinkage boom 24 is selectively operable by associated power means 26 toraise and lower two laterally offset spray guns 28 into alternatespraying positions substantially normal to and proximately spaced fromthe front and rear body panels 30 and 32 or the intermediate verticallyoffset roof panel 34 for various vehicle body types. The gun supportinglinkage or boom 24 is in turn supported for transverse reciprocatingmovement relative to the frame by a compound motion transmittingparallelogram linkage 36 of relatively compact lightweight construction.This compound linkage is operably connected to a drive mechanism 38 anddriven to provide substantially constant-velocity straight-linereciprocating move ment of the spray guns transversely of the severalvehicle body surfaces. The compound linkage 36 includes a framesupported parallelogram linkage and a second parallelogram linkagesupported by a horizontal link common to the frame mounted link-age. Theconveyor adjacent end of a second horizontal link pivotally supports thegun carrying linkage 24. A motion controlling guide means is associatedwith and counterswin-gs the second parallelogram linkage opposite to theswinging motion of the frame supported parallelogram linkage. Suchcounterswinging of these two linkages imparts substantiallystraight-line reciprocating move-ment to the second horizontal link andto the spray gun supporting linkage mounted thereon.

The frame mounted linkage includes two parallel links 40 and 42pivotally mounted at 44 and 46, respectively, on a horizontal bottombeam 48 of the vertical frame portion. The upper ends of these two linksare pivotally connected at 50 and 52 to opposite ends of a horizontallink 54 and to the upper ends of the two depending parallel links 56 and58. In the extreme positions of the link 54 shown in full and phantombroken lines in FIGURE 1, the links 40 and 42 are inclined laterallyupwardly at equal angles of approximately 45 to vertical planesincluding their lower pivotal axes 44 and 46. The links 40, 42 and 54thus cooperate with the lower beam of the frame 11 to define. anupstanding parallelogram linkage swingable through a 90 are relative tothe lower pivotal connections 44 and 46.

The lower ends of the links 56 and 58 are pivotally connected at 60 and6 2 to opposite ends of a second horizontal link 64 equal in effectivelength to the first horiz-ontal link 54. A short bell crank arm 66depends from the end of the link 64 adjacent the pivotal connection 62.This bell crank arm serves as a link pivotally mounting the laterallyadjacent end of the spray gun supporting linkage 24. The links 56 and 58are preferably equal in effective length to the links 40 and 42 andcooperate With the horizontal links 54 and 64 to define a dependingparallelogram linkage. The upper end of a motion translating control armextension 68 of the link 56 is pivotally connected at 70 to a clevisformed in a bearing block 72. This bearing block is sliclable betweentwo frame supported crosshead bearing members 74. By thus restrainingmovement of the upper pivotal connection 70 of the control arm to avertical reciprocating path any driving motion imparted to thehorizontal link 54 rotates the control arm link 56, 68 about itsrestrained upper pivotal connection 70. Such control arm rotation swingsthe depending parallelogram linkage oppositely of the frame supportedlinkage. The resultant straight l-ine reciprocating movement imparted tothe horizontal link 64 doubles the horizontal translation of the link 54and thus carries the spray-gun-supporting boom linkage 24 transverselyof the vehicle body between its extreme retracted and extendedpositions.

The spray-gun-supporting quadrilateral linkage includes a primary bellcrank lever 76 pivotally mounted at 78 with respect to the depending arm66 of link 64. This lever has a relatively long boom arm 79 extendinglaterally toward the conveyor line and swingaeble in a vertical planeabout its pivotal mounting. A relatively short bell crank arm 80 extendsupwardly from the pivotal mounting of the lever 76 and is operablyconnected at 82 to a piston rod 84 projecting from a doubleacting fluidpressure motor 86. The piston of this motor is reciprocably mounted in acylinder 88. To accommodate swinging movement of rod-to-lever connection82, the cylinder is pivotally mounted at 98 on the horizontal link 64 bya bracket 92. Opposite ends of cylinder 88 are alternately connectableby proper operation of the various controls to a source of actuatingfluid pressure. Such selective supply of fluid pressure to the motorcylinder alternately actuates the piston in opposite directions therebyswinging the lever 76 to raise or lower the spray-gun-supportingswinging end of the boom arm 79 relative to the adjacent vehicle body.

A relatively short, vertically maintained link 96 is pivotally connectedat 94 to the swinging end of the boom arm. The link 96 adjustably mountsan inverted T- shaped bracket 98. The cross bar of this T-shaped memberis preferably inclined obliquely of the conveyor line and adjustablymounts the spray guns 28 in laterally offset, spray-overlapping relationto s-ubadjacent surfaces of the conveyor transported vehicle bodies. Acontrol link 100 is pivotally connected at 102 and 104 to the verticallink 96 and to the depending arm of the horizontal link 64 and extendsthe-rebetween in slightly spaced, substantially parallel relation abovethe boom arm of lever 76. This control link maintains thespray-gun-supporting link 96 in normal vertical relation to the vehiclebody surfaces being sprayed irrespective of the spray gun elevationeffected by the selective euergiz'ation of the fluid pressure motor Sfiand the resultant swinging of the lever '76.

The drive mechanism 38 imparts substantially constant velocityhorizontal movement to the link 54 and thus to the boom supported sprayguns as they traverse the several offset vehicle body surfaces. Thisdrive mechanism includes a vertical plate 106 carried by the link 54. Acrosshead slot 188 in this plate slidably mounts a bearing block 111}having a journaled driving connection at 112 with a link drive chain114. The chain 114 drivingly interconnects a motor driven sprocket 116and an idler sprocket 118. These sprockets are respectively journaled at120 and 122 in a drive housing 124 and a bracket 126 suspended from theupper frame portion. The housing 124 miunts a variable speed electricmotor 128 selectively connectable to drive the sprocket 116 by a driveestablishing coupling and speed reducing unit 130' also mounted Withinthe housing 124. The speed of the motor 128 is synchronized withconveyor speed and selective operation of the boom controlling powermeans 26 and of the drive establishing coupling 130 coordinated by amotor driven timing mechanism 132 in accordance with a control indicatedbody style. As shown in FIGURE 2, the timing mechanism 132 iscontinuously driven by the motor 128 during operation of the sprayingapparatus by a second chain drive 134 and thus synchronized withconveyor vehicle body movement.

The .paint spraying machine of the invention may be automaticallycontrolled by operation of a suitable body style and color programmingremote control console, not shown. In the illustrative embodiment,however, the machine is conditioned for spraying operation by the manualcontrol 20. This control may also serve to energize the conveyor. Aseach conveyor transported vehicle body reaches the spraying station, acontrol signal generated by the spaced proximity sensing control units136 and 138 of the automatic control 22 and/or by the motor driventiming mechanism is supplied to the control console 18. This signalmaintains or vertically positions the retracted spray guns for sprayingof the front panel, conditions the spray guns to commence the sprayingoperation and energizes the drive coupling to effect motor drivenreciprocation of the spray-gun-supporting boom 24. A control signalsubsequently supplied by either the timer or proximity controlsinterrupts the spraying operation and supplied fluid pressure actuatingthe double-acting motor 86 so as to swing the boom upwardly into properspray gun position for the approaching roof panel. A control signal thensupplied by either the proximity units or by the timer conditions thespray guns to commence their roof spraying operation with continuing orresumed reciprocation of the spray-gun-supporting boom relative to theconveyor transported body. As the spray guns reach the rear edge of theroof panel, the timing mechanism and proximity controls cooperate inaccordance with the body style selectively impressed on the timingcontrol to interrupt the spraying operation and effect a reversal influid pressure supply conditions to the motor 86. The boom supportedspray guns are thus lowered into proper spraying elevation forsubsequent control regulated spraying of the vehicle bndy rear deck. Aseach vehicle body reaches the end of the rear deck spraying station, theseveral controls cooperate to interrupt the spraying operation and todeenergize the drive coupling 130 and thus stop the reciprocating boomas it reaches its fully retracted position thereby permitting passage ofthe carriers supporting the spaced ends of adjacent bodies.

As best seen in FIGURE 1, the geometry of the spraygun-supportinglinkage is preferably such as to permit overtravel of the body surfaces32 and 34 at the end of each stroke to allow for the nonlinear motionencountered during drive reversal of the upper horizontal link bymovement of the swiveled chain driven connection 112 relative to thesprockets 116 and 118. Such non-linear motion serves to decelerate theboom during such overtravel of the boom linkage. The spray guns 28 maybe shut off during these periods of reversal by suitable shutoffcontrols associated with either the timer 132 or with the boomsupporting parallel linkages.

It should be noted that the spray guns do not, per se, constitute a partof the invention and have therefore not been described in detail. Inaddition, and solely for the purpose of simplifying the drawings, theair and paint supply lines norm-ally connected to such spray guns havegenerally been eliminated as have been the air and paint reservoirs andthe attending pumping devices, all of which would be necessary toactually spray paint.

From the foregoing description of a single illustrative embodiment, itwill be seen that the invention provides a relatively simple machinecapable of supplying the several stated objects and advantages of theinvention. It will be further apparent that various modifications andchanges might be made in and fro-m the disclosed embodiment, includingchanges of the several lengths and in the restrained movement of thecompound linkage to modify movement of the spray guns relative to theworkpiece object, without departing from the spirit and scope of theinvention as defined in the following claims.

I claim:

1. A spraying machine, comprising support means, a first parallelogramlinkage including a pair of first parallel links pivotallyinterconnected by a first intermediate link and each pivoted to thesupport means, a second parallelogram linkage including a pair of secondparallel links pivotally interconnected by the first intermediate linkand pivotally interconnected by a second intermediate link, the secondparallel links being equal in length to the first parallel links, spraymeans, means mounting the spray means on the second parallelogramlinkage, means for swinging the first parallelogram linkage, cOntrolmeans interconnecting one of the second parallel links and the supportmeans to impart a coordinated opposite,

swinging movement to the second parallelogram linkage upon swingingmovement of the first parallelogram linkage to thereby efiect movementof the spray means in a rectilinear path.

2. The machine recited in claim 1, wherein the mounting means includes aquadrilateral linkage pivotally interconnecting the spray means and thesecond parallelogram linkage, and operating means operably connected tothe quadrilateral linkage for effecting swinging movement of the spraymeans relative to its rectilinear path of movement.

3. The machine recited in claim 2, wherein the quadrilateral linkageincludes a mounting link mounting the spray means, and a pair of thirdparallel links of equal length pivotally interconnecting the mountinglink and the second parallelogram linkage.

4. The machine recited in claim 3, wherein each of the third parallellinks is pivoted to the second intermediate link, one of the thirdparallel links includes a power arm extending therefrom, and theoperating means is mounted on the second intermediate link, theoperating means being operably connected to the power arm to pivot thesaid one third parallel link about its pivot to the second intermediatelink and thereby effect swinging movement of the spray gun relative toits rectilinear path of movement.

5. The machine recited in claim 1, wherein the control means includes aguide member mounted on the support means, a control arm extending fromone of the second parallel links, and a slide member pivoted to thecontrol arm and received by the guide member for sliding movement normalto the rectilinear path of moveent of the spray means during swingingmovement of the first and second parallelogram linkages.

6. A machine for spraying surfaces on a plurality of conveyortransported objects, comprising a frame member mountable laterally andin suspended spaced relation above the surfaces of said objects, a firstparallelogram linkage comprising first and second links of equal lengtheach pivotally connected at one end thereof on said frame member forswinging movement transversely of the surfaces on said objects and athird link pivotally interconnecting said first and second links inequispaced parallel relation to the frame pivoted ends thereof, motormeans operably connected to one of said first three links and adapted toimpart oscillatory swinging movement to said first parallelogramlinkage, a second parallelogram linkage pivotally supported by saidthird link member and including fourth and fifth links equal in lengthto said first and second links and pivotally connected therewith toopposite ends of said third link, a sixth link pivotally interconnectingsaid fourth and fifth links in equispaced parallel relation to saidthird link member, selectively remotely operable means for spraying thesurfaces on said objects supported by said sixth link, and a thirdlinkage supporting said spraying means on said sixth link for movementnormal to the surfaces to be sprayed on said objects, said third linkageincluding a spray gun supporting link, a pair of links pivotallyconnected to and supporting said spray gun supporting link intransversely spaced relation to said sixth link, and motor meansselectively energizable and operably connected to swing said thirdlinkage to adjust said spray gun supporting link normally of thesurfaces on said objects, one of said fourth and fifth links having acontrol arm extending beyond its pivotal conecting to the third link,guide means for pivotally mounting the distal end of said control armfor restrained movement translating the oscillatory swinging movementimparted to said third link into opposite oscillatory movement of saidpaired first and second links and of said fourth and fifth links,thereby multiplying the swinging movement imparted to said third linkand effecting substantially rectilinear movement of the spraying meanssupported by said sixth link.

References Cited by the Examiner UNITED STATES PATENTS 2,840,037 6/1958Verba 118321 X 2,955,568 10/1960 Blenman et al. l18323 FOREIGN PATENTS210,712 8/1960 Austria.

DANIEL BLUM, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,286,688 November 22, 1966 William G. Blenman It is hereby certifiedthat error appears in the above numbered patent requiring correction andthat the said Letters Patent should read as corrected below.

read mounts Column 3, line 52, for "miunts" column 4, line 8, for"supplied" read supplies line 23, for "bndy" read body column 6, line24, for "conecting" read connection Signed and sealed this 12th day ofSeptember 1967.

( AL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. A SPRAYING MACHINE, COMPRISING SUPPORT MEANS, A FIRST PARALLELOGRAMLINKAGE INCLUDING A PAIR OF FIRST PARALLEL LINKS PIVOTALLYINTERCONNECTED BY A FIRST INTERMEDIATE LINK AND EACH PIVOTED TO THESUPPORT MEANS, A SECOND PARALLELOGRAM LINKAGE INCLUDING A PAIR OF SECONDPARALLEL LINKS PIVOTALLY INTERCONNECTED BY THE FIRST INTERMEDIATE LINKSAND PIVOTALLY INTERCONNECTED BY A SECOND INTERMEDIATE LINK THE SECONDPARALLEL LINKS BEING EQUAL IN LENGTH TO THE FIRST PARALLEL LINKS, SPRAYMEANS, MEANS MOUNTING THE SPRAY MEANS ON THE SECOND PRALLELOGRAMLINKAGE, MEANS FOR SWINGING THE FIRST PARALLELOGRAM LINKAGE, CONTROLMEANS INTERCONNECTING ONE OF THE SECOND PARALLEL LINKS AND THE SUPPORTMEANS TO IMPART A COORDINATED OPPOSITE SWINGING MOVEMENT TO THE SECONDPARALLELOGRAM LINKAGE UPON SWINGING MOVEMENT OF THE FIRST PARALLELOGRAMLINKAGAE TO THEREBY EFFECT MOVEMENT OF THE SPRAY MEANS IN A RECTILINEARPATH.